I've used Profnet several times and been very pleased with the experts I've connected up with.

I guess you might consider it free publicity for them, but if you need the voice of experience to quote from to give your article more clout, then you're probably going to need to give the expert or their organization a plug in your article. They aren't charging you a monetary fee for their expertise; it does take up a bit of their time, so a mention of their book or column or research, etc. doesn't seem out of line.

My experience with them has been very good. I have only been disappointed in one instance, when the experts just didn't seem to be available on the subject matter I needed quotes for.

The experts I've been put in touch with range from columnists, doctors, therapists, pet trainers, etc. Some had a book on the market, another had a column, etc. I've never been asked to do anything other than a "mention" of the experts name and book. . .certainly nothing I ever felt was "selling" for them.

From what I understand, the organization is well thought of in the writing community. Maybe others will weigh in on this subject. I'll be interested too.